AC-to-DC converters may convert an AC (alternating current) input voltage into a DC (direct current) output voltage using a single-stage scheme or a multi-stage scheme. A single-stage AC-to-DC converter has relatively high conversion efficiency, relatively simple control logic, a relatively small number of elements and a relatively low cost as compared to a multi-stage AC-to-DC converter. How the single-stage AC-to-DC converter can be undamaged over a relatively wide range of input voltages and can simultaneously provide the output voltage with a relatively small ripple component is important.